Genetic Markers Allow Mice To Recognize Relatives They've Never Met

Since mice generally look very similar to one another, they rely on scent to recognize close relatives. Female mice use this to seek compatible nest mates, according to researchers from the University of Liverpool. They can even distinguish close relatives they have never met before.

Using genetic analysis, researchers concluded that mice have a species-specific genetic marker called the major urinary protein (MUP), which the mice can detect using their sense of smell. This contradicts previous assumptions that the animals use a system called vertebrate-wide major histocompatibility complex (MHC) to recognize kin, according to a news release.

Female house mice rely on this scent in order to select closely related females as nest partners to help look after their offspring. Most species, including humans, use this partnership as a way to ensure that genes are properly passed down to future generations.

"This work extends far beyond any previous attempt to identify the genetic basis of kin recognition in vertebrates and strongly challenges the current assumption that there is a common kin-recognition mechanism 'inbuilt' into the immune physiology of all vertebrates," Professor Jane Hurst, from the university's Institute of Integrative Biology and lead author of the study, said in a statement.

This study could help researchers understand how other species evolved with similar genetic markers to recognize relatives and what affect it has on breeding success.

"We also need to consider the consequences in species that have not evolved these markers -- are they more vulnerable to inbreeding accidentally with relatives that they cannot recognize?" Hurst added. "More widely, a better understanding of the importance of social groupings in populations could also have implications for captive breeding programs and help those managing animals promote better cooperation and social tolerance among animals."